Firstly I'd like to say that I'd highly doubt that a ball python would literally try to choke you with the intent of killing you. In my experience, whenever a ball python has tightened around my neck, it was an insecurity response because I either made a sudden loud noise with my voice or there was a fast movement nearby, etc.
That being said, I highly doubt an adult BP would be able to do any sugnificant damage to a healthy adult human (toddlers maybe, but past the age of say, 10 I don't think there would be any problems). Cause discomfort, most definitely, but I highly doubt they could do any real damage.